Generally, during the traditional percutaneous endoscopic procedures, such as minimally invasive percutaneous nephrolithotomy, irrigation fluid with a predetermined safe pressure and flow is perfused into intrarenal pelvicaliceal system through the working channel of the endoscopy. The reasons are as follows:
1. Artificially dilating the pelvicaliceal system to expose the surgical area;
2. Washing the surgical area to maintain a clear endoscopic vision;
3. Cleaning the surgical area and clearing the bacteria or endotoxins;
4. Flushing out the substances like fragmented stones by the different pressure between internal and external renal when withdraw the endoscope.
At the beginning of traditional percutaneous endoscopic procedures, such as minimally invasive percutaneous nephrolithotomy, a proper size percutaneous puncture tract should be established at first as needed. Meanwhile, an endoscope matched with the percutaneous puncture tract should also be selected. During the procedure, further percutaneous puncture tract dilation would be carried out, or multiple percutaneous puncture tracts would be used, if needed.
The primary intraoperative complications of traditional percutaneous endoscopic procedures, such as minimally invasive percutaneous nephrolithotomy, are as follows:
1. Sepsis. Although the irrigation pressure and flow could be set within a safe range on the irrigation pump, maintaining low intraoperative intrarenal pressure was mainly achieved by evacuating fluid via the space between the percutaneous puncture access sheath and the endoscope, or by discharging fluid through percutaneous puncture access sheath to external body when withdraw the endoscope. If irrigation pressure beyond the upper limit of predetermined safe parameter persistently, especially when infectious diseases coexist, sepsis will remarkably increase.
2. Residual stones. When the irrigation pressure is lower than intrarenal pressure, the unbalance between irrigation and evacuating fluid would cause unclear in traoperative field visibility, and subsequently the difficulty of procedures would increase, which lead to residual stones or more sessions required.
3. Bleeding.